KR20060120617A - Motor vehicle forebody structure - Google Patents

Abstract

The invention relates to a motor vehicle forebody structure (1). The invention consists of: (i) an upper part (10) comprising at least two side members (11) which extend longitudinally in front of the passenger compartment of the vehicle and which are connected at the front end thereof by a cross member (13) which, in the event of a front-end collision, absorbs a sufficient quantity of energy in order to minimise deformation of the side members (11); and (ii) a lower part (20) comprising at least one frame cradle (21) which supports the functional elements of the vehicle, which is formed by at least two longitudinal arms (22) that extend towards the front of the vehicle, and which is connected to the side members (11) of the upper part (10) by means of vertical bars (30). The invention is characterised in that the structure (1) comprises shock absorbers (25) which are fixed to the frame cradle (21) towards the front of the vehicle, and in that the main dimension of said shock absorbers (25) is longitudinal, such that, in the event of a front-end collision, the absorbers (25) absorb sufficient energy in order to minimise frame cradle (21) deformation.

Description

Front part of car {MOTOR VEHICLE FOREBODY STRUCTURE}

The present invention relates to the front structure of a motor vehicle.

More specifically, the present invention relates to an upper portion formed of at least two side members extending in front and rear directions in front of a passenger compartment of a vehicle and having a front end connected by a cross member. The front end, which absorbs a sufficient amount of energy to minimize deformation of the side member in the event of a collision) and at least two longitudinal arms extending towards the front of the vehicle and connected to the upper side member by a vertical bar A structure of the type having a lower portion formed of at least one frame cradle supporting a functional component of the invention.

This type of structure can independently solve at least two distinct mechanical properties, namely suspension and frontal impact treatment. The lower part of the structure known to the person skilled in the art as the term "low way" comprises a functional part of the vehicle, such as an engine transmission unit, via a cradle. This low way is in the " disconnected " portion of the cradle, which can mitigate vibrations caused by the running of the vehicle on the road and the engine being supported. The upper portion of the structure, known to those skilled in the art as "high way", can withstand frontal impacts due to the restoring force of the side members. Therefore, such highways must absorb energy following large impact loads so as not to break into the cabin due to impact.

The manufacturer wants to absorb increasingly heavy loads in the event of a frontal impact to ensure maximum safety for the passengers. However, constraints on the architecture, weight and aesthetics of the vehicle hinder the enlargement of the thickness and length dimensions of the side members to withstand the load.

Document EP-B1-0926048 discloses and shows a subsidiary chassis located under the side member, wherein energy absorbed by the left and right absorbing parts located in front of the side member and the subsidiary chassis is interposed between the side member and the subsidiary chassis. Distributed. This distribution results in a very large deformation of the subsidiary chassis in the case of a large front shock, for example a shock between two vehicles, so that a small shock, for example a pedestrian, may be applied to the vehicle at the bumper level as mentioned in the detailed description above. This applies in the case of conflicting "pedestrian shock".

In fact, the large forward and backward loads on the front and rear absorbing parts in front of the subsidiary chassis lead to the left and right constraints on the front and rear parts of the subsidiary chassis during the curve breaking of the part, ie during the first straight return from the curved. The parts can be spaced apart and weakened.

The front structure must actually manage two types of different impacts, small impacts such as the "pedestrian shock" described above that generate small energy absorbed by the vehicle, and impacts with large energy. Such high energy-dissipating shocks are of the "Danner shock" type, i.e. low-speed shocks with limited replacement of structural parts only, or "which should not result in deformation of the cabin for optimum passenger safety." May be of the "crash" type.

Such different impacts are difficult to manage in the same zone of the vehicle. Therefore, it is known to add a foam for the treatment of "pedestrian impact" on the cross member for treating the alternator impact, but in this case the treatment of "pedestrian impact" is not optimized. Thus, it is known to provide a "pedestrian shock" bar located at the "low way", which is effective for this type of shock but is impossible to mount another absorbent component.

It is therefore an object of the present invention to obtain a less solid vehicle front structure which can distribute the energy absorbed when impacted without damaging the underside of the vehicle.

It is also an object of the present invention to obtain a structure in which the lower portion thereof can cope with "pedestrian shock" and "daner shock".

To this end, the present invention has a shock absorber fixed on the frame cradle towards the front of the vehicle, and the main dimension of the shock absorber to absorb enough energy to minimize deformation of the frame cradle in the event of an impact on the front face. It is proposed a structure of the front part of the vehicle described above, characterized in that it is in the front-rear direction.

Therefore, the presence of the shock absorber 25 fixed on the frame cradle makes it possible to distribute the load induced by the impact between the upper part of the front part (absorption by the cross member) and the lower part of the front part (absorption by the shock absorber).

According to a feature of the invention, the structure comprises a shock absorber whose main fore and aft axis is located on the vertical central plane of each longitudinal arm of the frame cradle.

With this arrangement of shock absorbers, they can be free from the load component induced in the lateral direction and weaken by spacing the longitudinal arms from each other. The shock absorbers are positioned at substantially the same height as the longitudinal arms of the frame cradles so that loads not received by the shock absorbers are transferred from the front and rear extensions to the frame cradle arms. According to one variant, the shock absorber is located at a height lower than the longitudinal arms of the frame cradle.

According to one aspect of the present invention, the front and rear direction dimension value of the shock absorber is such that the front end of the shock absorber is in the front and rear direction when the front end of the cross member of the upper part retreats before the impact. Therefore, the absorption of energy is first made by the cross member front end located on the highway, and then, when the impact is large, the cross member and the shock absorber located on the low way are simultaneously performed.

The present invention also contemplates the management of small impacts of the pedestrian impact type. For this purpose, a cross bar is placed in front of the shock absorber at the lower level.

This cross bar is secured to the frame cradle through substantially front and rear posts and at least one center post whose major axis is located on the vertical center plane of each front and rear arm of the frame cradle.

According to a feature of the invention, the shock absorber is mounted on the side post.

In order to realize the one-piece structure forming the subunit, the structure advantageously comprises a single member formed of a buffer and a side post on the vertical center surface of each front and rear arm of the frame cradle, or shaped into one member. Cross bars, side posts, and shock absorbers.

Other features and advantages of the present invention will appear in the following description, and for purposes of explanation, reference will be made to the accompanying drawings.

1 is a schematic perspective view of a front structure of a vehicle according to a first embodiment of the present invention.

2 is a front view of the structure according to the embodiment shown in FIG. 1.

FIG. 2B is a view similar to FIG. 2, in a first impact step. FIG.

FIG. 2C is a view similar to FIG. 2B, in a second impact step. FIG.

3 is a side view of the front structure according to the second embodiment of the present invention.

4 is a plan view of the front structure according to the embodiment shown in FIG.

5 shows schematically a part of a structure according to a second variant.

6 shows schematically a part of a structure according to a third variant.

7 shows schematically a part of a structure according to a fourth variant.

In the following description, as a non-limiting example, the longitudinal direction, the vertical direction and the transverse direction will be adopted according to the orientation conventionally used in the automobile field and represented by three letters of L, V, and T.

The structure according to the invention is generally symmetrical with respect to the longitudinal center plane in the fore and aft direction. The front part structure 1 of the vehicle according to the invention, as shown in FIGS. 1, 2, 2b and 2c, in principle, extends towards the front part by the case 12 and is fixed to the front end of the case 12. The upper part 10 is formed in a substantially horizontal plane from the compartment to the front part of the vehicle by the side member 11 connected in the left and right direction by the cross member 13.

The structure 1 also has a lower portion 20 at a height substantially lower than the height of the upper portion 10 in the horizontal plane. This lower part is provided with a frame cradle 21 which serves to secure support of the vehicle, more specifically the functional parts of the engine. This frame cradle 21 is formed by at least two longitudinal arms 22, the front end of which is connected by a transverse arm 23, from the cabin toward the front of the vehicle. In this lower portion 20, a shock absorber 25 is fixed on the frame cradle 21, in front of the longitudinal arm 22.

The lower part 20 is connected to the upper part 10 by the vertical post 30, and the vertical post is disposed near the front end of the upper part 10 and the lower part 20. The post 30 may maintain the frame cradle 21 to generate a load behind the shock absorber 25.

As shown in the figure, the shock absorber 25 has a truncated conical shape whose main axis is the front-rear direction, and the base having a small diameter is located in the front-rear direction in front of the base having a large diameter fixed on the frame cradle 21. The shock absorber may be of another type (eg cylindrical) as long as the maximum dimension of the absorber is substantially in the forward and backward direction without departing from the context of the present invention.

The base 27 having a large diameter of the conical shock absorber 25 is fixed to the frame cradle 21, and the front end thereof has a free end of the shock absorber 25 at the front position of the vehicle at the initial position before the impact shown in FIG. It should extend toward the front part of the vehicle so that it is located in the front-rear direction in the recessed part of the cross member 13 of the upper part 10 with respect to.

Therefore, when a large impact is received on the front surface, residual energy induced from the impact is initially absorbed by the cross member 13 of the upper portion 10. This cross member 13 has geometrical features and is precast concrete to absorb most of the impact energy. The curved cross member 13 facing the front of the vehicle, before the impact, causes compression of the case 12 which is subjected to the curved stripping and subsequently fixed to the front end of the side member 11. The front end of the cross member 13 is located and the vertical plane representing the impact surface Pi retreats in the vehicle direction.

If the frontal impact is very large, the safety body will prevent the impact surface from retracting into the interior of the cabin.

In the case of the Danner shock, for the purpose of limiting the repair cost, the safety body has an impact surface Pi at the front end of the side member 11 of the upper part 10 and at the front end of the frame cradle 21 of the lower part 20. Prevents retreating up.

In order to obtain a safety body suitable for each impact, the energy caused by the different impacts is transmitted by the shock absorber 25 of the lower portion 20 and the cross member 13 and the case 12 of the upper portion 10 to the impact surface. After a predetermined retreat of is absorbed.

2, 2B and 2C show an example of the impact, where the energy absorbing portion is secured by the shock absorber 25 of the lower portion 20. 2 shows a rest situation, where the front end of the cross member 13 is L away from the compartment. The front end of the shock absorber 25 is separated from the compartment by one less than L corresponding to the cross member 13. Therefore, the impact surface Pi is a vertical surface through which the end of the cross member 13 passes by L from the vertical surface of the vehicle compartment.

2b shows the first impact stage. This impact is large enough to cause deformation of the case 12 and the cross member 13 and to displace the impact surface Pi toward the vehicle compartment. Since the distance of the cross member front end to the compartment is equal to the distance of the shock absorber front end to the compartment, the impact surface Pi includes the front end of the shock absorber 25. If the impact is large enough so that the energy to be absorbed remains, this absorption is achieved by the case 12 and cross member 13 of the case 12 and the shock absorber 25 of the lower portion 20 (see FIG. 2C). ).

Shock can be divided into three types

In the case of a weak impact, the impact surface Pi does not reach the front end of the shock absorber 25, so that the shock absorber 25 is in a complete state after the shock disappears, and the cross member 13 and optionally the case 12 You only need to replace it.

In the case of Daener impact, the impact surface Pi reaches the front end of the shock absorber 25 and continues to retreat toward the compartment while deforming the shock absorber 25, but the front end of the cross member 13 also has a side member ( It does not reach the front end of 11). The shock absorber 25 can secure an energy absorbing portion, and can prevent the impact surface Pi from retreating to the side member 11 or the frame cradle 21 toward the vehicle compartment. Thus, the cross member 13, the case 12 and the shock absorber 25 should be replaced while the side member 11 and the frame cradle 21 are complete.

Finally, in the case of severe impact, the impact surface Pi retreats toward the vehicle compartment and exceeds the front end of the side member 11. Since the entire front structure 1 is deformed, the entire front structure 1 must be replaced, but energy absorption is achieved by the cross member 13, the case 12, and the side member 11. By (21) it can be made at the same time in the low way, there is no penetration into the cabin and there is no need to ensure the safety of the passengers.

As can be clearly seen in FIG. 1, the shock absorber 25 is disposed in the left-right direction such that the axis corresponding to the main direction in the front-rear direction is located on the same vertical plane as the longitudinal axis of the side member 11. According to this arrangement, in particular, when the shock absorber 25 is compressed by the impact, the load may not be transmitted to the frame cradle 21 of the lower portion 20 along the horizontal axis component. The object of the invention in which the longitudinal arms 22 are not spaced apart from each other and the load that weakens the frame cradle 21 is not transmitted along the transverse component can be achieved according to two variant embodiments.

In the first variant shown in FIGS. 1, 2, 2b and 2c, the shock absorber 25 is located in the extension of each longitudinal arm 22. When the shock absorber 25 is compressed, the load is all transmitted from the shock absorber 25 toward the longitudinal arm 22.

In a second variant, not shown, the shock absorber 25 is located at a height higher than the frame cradle 21. Thus, the load is transmitted from the shock absorber 25 toward the longitudinal arm 22 along the main part and the vertical axis part in the front-rear direction. It will be appreciated that the shock absorber 25 may be located at the same height as the longitudinal arm 22 but may be located at a height between the side member 11 and the frame cradle 21. The shock absorber 25 may even be located at a height lower than the frame cradle 21 and will provide a sufficient distance between the driveway and the bottom of the vehicle if the height is kept at ground level.

3 and 4, the lower portion 20 of the front portion structure 1 according to the present invention can be used with a pedestrian impact treatment apparatus in a low way. This device consists of a cross bar 41 located in front of the shock absorber 25. This bar 41, which is substantially parallel to the transverse arm of the frame cradle 21, is connected to this frame cradle via a front-rear post 42. The length of the post 42 is such that the cross bar 41 is positioned in front and rear directions in front of the shock absorber 25 of the lower part 20 and advantageously in front of the front end of the cross member 13 of the upper part 10. .

According to different variations of the second embodiment, the number of posts 42 may vary, preferably at least three. The cross bar 41 is held by at least two side posts 43 and one central post 44. The number of center posts 44 may vary. The side post 43 extends substantially in the front-rear direction at the extension of the longitudinal arm 22 of the frame cradle 21. By arranging the side posts 43 in the horizontal direction, the load generated as a result of the pedestrian impact can be optimally recovered on the longitudinal arm 22.

The side post 43 and the shock absorber 25 are fixed on the frame cradle 21 on the substantially same side, that is, on the axis of the longitudinal arm 22 of the frame cradle 21. 3 and 4 show a first variant of the second embodiment with a pedestrian impact treatment apparatus in a low way. In order to be located in the extension of the longitudinal post 22 of the side post 43 and the shock absorber 25, the shock absorber 25 is provided with a groove in the lower portion to allow passage to the side post 43 receiving portion. Can be.

In the case not shown, where the shock absorber is located at a height lower than the frame cradle, the receiving portion for the passage of the side post 43 is made up of a groove above the shock absorber 25.

FIG. 5 shows a second variant of the second embodiment with a pedestrian impact treatment apparatus in a low way. The structure according to the invention allows a single member 45 formed by the engagement of the shock absorber 25 and the side post 43 so that it can be located in the extension of the longitudinal arm 22, the shock absorber 25 and the side post 43. ) May be provided. The single member 45 has a first portion corresponding to the side post, which is precast concrete under a predetermined first load so as to absorb energy generated by the pedestrian impact, and a predetermined portion so as to absorb energy generated by the damner impact. And a second portion corresponding to the shock absorber, which is precast concrete under a second load of. Different precast concrete is obtained by varying the ribs and thicknesses of the two parts of the single member 45. The cross bar 41 is preferably fixed to the inner surface of the bumper, ie the bumper surface oriented towards the vehicle.

FIG. 6 is a third modification of the second embodiment with a pedestrian impact treatment apparatus in a low way. FIG. The structure according to the invention is formed of a cross bar 41, a side post 43 and a shock absorber 25 so that it can be located in the extension of the longitudinal arm 22, the shock absorber 25 and the side post 43. It may have a single unit 46. In this case, the unit 46 that is heavier than the single shock absorber 25 must be screwed onto the frame cradle 21 so that the weight towards the front of the unit 46 is not overly cumbersome.

A single unit 46 as shown in FIG. 7 may have an internal streamline 47 extending substantially horizontally below the cross bar 41 and the front and rear posts 42. The single unit 46 is shaped such that when the front structure 1 is mounted the inner streamline 47 is continuous with the streamline below the engine transmission unit. In embodiments with a single unit 46 the mounting of the front structure can be facilitated and the structure can be easily replaced when impacted.

Combining these various modifications, as shown in FIG. 3, a pedestrian in a highway, of the type having a foam 14 which covers the front end of the cross member 13 of the upper part 10 in the lateral direction. An impact treatment apparatus can be provided.

Claims (10)

Upper part 10 (the cross member) formed of at least two side members 11 extending in the front-rear direction in front of a passenger compartment of the vehicle and whose front end is connected by a cross member 13. 13 is formed by absorbing a sufficient amount of energy to minimize deformation of the side member 11 when the front end collides) and at least two longitudinal arms 22 extending towards the front of the vehicle and Lower portion 20 formed by at least one frame cradle 21 for supporting a functional part of the vehicle, which is connected to the side member 11 of the upper portion 10 by a vertical bar 30. As the front part structure (1) of the automobile provided with The structure 1 has a shock absorber 25 which is fixed to the frame cradle 21 toward the front of the vehicle, and in order to minimize the deformation of the frame cradle 21 when the front end collides with the shock absorber 25. The front structure of a motor vehicle (1), characterized in that the main dimension of the shock absorber (25) is in the front-back direction so that the (25) absorbs sufficient energy. 2. The front structure of a motor vehicle according to claim 1, characterized in that the main shaft has a shock absorber (25) located on the vertical center plane of the longitudinal arm (22) of each of the frame cradles (21). 3. The front structure of a motor vehicle as claimed in claim 1 or 2, comprising a shock absorber (25) located at substantially the same height as the longitudinal arm (22) of the frame cradle (21). 3. The front structure of a motor vehicle as claimed in claim 1, further comprising a shock absorber (25) located at a height lower than the height of the longitudinal arms (22) of the frame cradle (21). 4. 5. The front end of the cross member 13 of the upper portion 10 according to any one of claims 1 to 4, wherein the main dimension is provided with the shock absorber 25 in the front-back direction, and before the impact, the front end of the shock absorber 25 Front part structure of the vehicle, characterized in that the front and rear direction at the time of retreat. The front part structure of the vehicle according to any one of claims 1 to 5, wherein the lower part (20) is provided with a cross bar (41) located in front of the shock absorber (25). A crossbar 41 fixed to the frame cradle 21 through substantially front and rear posts 43 and 44, wherein the front and rear posts 43 and 44 have a major axis frame. A front structure of a motor vehicle, characterized in that it is two side posts (43) and at least one central post (44) located on the vertical center plane of each longitudinal arm (22) of the cradle (21). 8. The front structure of a vehicle according to claim 7, characterized in that it has a shock absorber (25) mounted on the side post (43). 8. An automobile according to claim 7, characterized in that it is provided with a single member (45) formed of a shock absorber (25) and a side post (43) on the vertical center surface of the longitudinal arm (22) of each of the frame cradles (21). Anterior structure of the. 8. The front structure of a motor vehicle according to claim 7, characterized by having a cross bar (41), a side post (43), a shock absorber (25) and a lower streamline (47) shaped as one member.

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